I know that RJ were working on how much power was required to get a bullet to penetrate the aircraft skin. Their riccochets were coming into my classroom
I guess that once it became common knowledge that RJ and El Al carried "air marshalls", terrorists decided other air lines would be much easier targets.
Certainly the do-gooders and weak management have screwed around long enough with aircraft security. Now terrorists need to know that they will not be the only ones on board who are dedicated to a cause.